The BAPIs are mentioned below
BAPI_COSTESTIMATE_GETLIST: Determine cost estimate lists
BAPI_COSTESTIMATE_GETDETAIL: Determine detailed information for a cost estimate
BAPI_COSTESTIMATE_ITEMIZATION: Determine itemization for a cost estimate
BAPI_COSTESTIMATE_GETEXPLOSION: Determine BOM explosion for a cost estimate
Execute BAPI_COSTESTIMATE_GETLIST first to get the list of cost estimates. Then you execute the other BAPIs
SAP has also provided the sample program SAPBAPICOPC to demonstrate, with examples, how to use these BAPIs
Br. Ajay M